Method for manufacturing a multi-layer composite, arrangement for positioning a sheet-like element onto a backing in a laminating unit

ABSTRACT

A method and an arrangement for manufacturing a multi-layer composite ( 13 ) by laminating a sheet-like element ( 6 ) onto a backing ( 2 ) in a laminating unit ( 1 ), having steps, in this order, of conveying the element ( 6 ) in a longitudinal direction, detecting a position of the element ( 6 ), correcting the position of the element ( 6 ) on the basis of the detected position and on the basis of a reference position ( 15 ), and bonding said element ( 6 ) onto the backing ( 2 ). The detection step comprises the phases of measuring the lateral position, an angle of pivoting, and a longitudinal position of the element ( 6 ), and the correction step includes phases of lateral movement (T), pivoting (P), and longitudinal movement (L) of the element ( 6 ), apparatus elements perform the steps.

BACKGROUND OF THE INVENTION

The present invention relates to a method for manufacturing amulti-layer composite by laminating a sheet-like element onto a backingin a laminating unit. The invention also relates to an arrangement forpositioning a sheet-like element onto a backing, to manufacture amulti-layer composite in a laminating unit. The invention relates to alaminating unit for manufacturing a multi-layer composite embodying sucha method and comprising such a positioning arrangement.

Multi-layer composite materials are used in the field of packaging,after they have been cut, folded and glued. One of these compositescommonly used is corrugated board. It is used mainly as a protectivepackaging that is particularly strong while being readily recyclable.

Corrugated board is for example made up of an inner board provided withcorrugations, bonded onto a first flat coverboard on one side of thecorrugations. This inner board with first flat coverboard constitutes asingle-face corrugated board. The single-face corrugated board obtainedis also assembled by bonding with a second flat board on the other sideof the corrugations.

To make the packaging more attractive, the corrugated board is oftenprinted. This operation is performed by flexography in order to obtainquality prints in multiple colors. However, printed corrugated board mayexhibit defects, for example in the case of relatively thin corrugatedboard. The defects are not acceptable for packaging for expensiveproducts.

Some printing defects among others are lines corresponding to each crestof the corrugations because, during printing, the corrugated board willbe crushed slightly. The difference in strength between the tops of thecorrugations and the regions separating two consecutive corrugations isthe main reason why these lines appear during the printing operation.

One technique then is to use laminating to assemble a sheet-like elementin the form of a preprinted sheet of board, onto a backing in the formof a single-face corrugated board.

The sheet-like element is for example paper sheet, cardboard sheet,corrugated cardboard sheet or flexible plastic sheet, which is rough orprinted, etc. The sheet-like element is already printed usingflexography, photogravure or offset printing or converted usingembossing, calendering or metallization by hot foil stamping, etc. Thebacking is for example paper board, cardboard, single-face corrugatedboard, double-face corrugated board or foam, etc.

To do this, a laminating unit comprises a section for feeding thesheet-like elements, the sheet-like elements being shingled, and asection for laminating the sheet-like elements onto the backings.

If the backings are in the form of boards, the laminating unit comprisesalso a section for feeding the backings. If the backing is in the formof a web, the laminating unit comprises also a section for cutting thisweb. The web comes from a reel or is produced in line upstream of thelaminating unit.

In the laminating section, the sheet-like element is bonded by pressingbetween two rolls onto the backing that has previously been coated withglue.

In order to obtain a quality composite, the positioning of thesheet-like elements in the laminating section is an operation of keyimportance. The sheet-like element has to be positioned accurately sothat later conversions are perfectly in register with the edges,printings, and/or conversions of the composite obtained.

PRIOR ART

Traditionally, alignment is performed by first of all bringing thesheet-like element against frontal end stops then against a lateral endstop, using a translational-drive member.

This approach inevitably leads to damage to the frontal and lateral edgeat the end stops and therefore to a loss of quality. In addition, thisalignment operation is performed in two stages, which entailstemporarily halting the sheet-like element and therefore a reduction inproduction rates.

Document EP-0,733,467 describes a method and a device for laminatingseparate topsheets onto a web of single-face corrugated board in alaminating machine in order to form double-sided corrugated sheets. Themethod comprises a first step in which the topsheets are fed from astack and directed toward a laminating roll positioned downstream. In asecond step, the single-face web is fed in and cut to length by a blade.In a third step, each topsheet is guided over a variable-speedpositioning roll. In a fourth step, the speed of the positioning roll isadjusted in order to establish a desired position of the front edge ofthe topsheet with respect to the front edge of the web in the laminatingroll. In a fifth step, a position of the rear edge of the topsheet inthe positioning roll is detected. In a sixth step, the cutting blade isactuated on the basis of the detected position of the rear edge of thetopsheet. This allows the web to be cut and yields a rear edge of thecut-to-length web that is in a desired position with respect to the rearedge of the topsheet.

However, with such a method, the topsheets reach the positioning rolland then the laminating roll in a position that may prove inappropriate.This is because the sheets, the central longitudinal axis of which isnot aligned with the central longitudinal axis of the laminatingmachine, will undergo only a longitudinal correction through a slowingor accelerating of the positioning roll. These misaligned sheets arebonded onto the single-face corrugated web with an offset, and this isundesirable in terms of the quality of the multi-layer composite that issupposed to be obtained.

Further, with such a method, the front edge and rear edge of thetopsheet are identified incorrectly, these not being perpendicular tothe central longitudinal axis of the laminating machine. This pivotingof the sheet with respect to the transverse direction means that theactuation of the cutting blade will not be synchronized with thedetection of the rear edge. This leads to incorrect lengths when cuttingthe corrugated web.

The higher the speed of the laminating machine, the higher thepercentage of misaligned sheets at the laminating roll because of thefast pace at which the topsheets taken from the pile by the feederarrive.

Document FR-2,857,655 discloses a method and a device for aligning amaterial in sheet form passing through a machine that works it. In afirst step, a sheet is brought onto a table, being taken from a layer ora series of sheets. In a second step, the sheet is conveyed into thevicinity of a conveying member that has two independent drive members.In a third step, a lateral and angular position of this sheet isdetected, and in a fourth step, the independent drive members of theconveying member are actuated differentially as the sheet moves, inorder to correct the lateral and angular errors in the positioning ofthis sheet.

Because of the independent drives of the members, the sheets progressfrom a first pivoted position into a second pivoted position and so on,until an aligned position is reached. However, such successive angularcorrections demand that the sheet be moved longitudinally over a longlength. The corrections are incomplete and are therefore imprecise withsheets of small sizes, the latter arriving in quick succession one afteranother. Conversely, the corrections are incomplete and thereforeimprecise for sheets of larger dimensions because of the larger anglesof pivoting to be corrected and because of the inertia of the sheetsthat has to be overcome.

In addition, these corrections through successive angular movements taketime and are therefore incompatible with an increase in overallproduction rates. The sheets have a particularly smooth surface and arenot effectively corrected by these successive angular adjustments.

SUMMARY OF THE INVENTION

It is a main objective of the present invention to develop a method formanufacturing a multi-layer composite by laminating a sheet-like elementonto a backing. A second objective is to develop a laminating method inwhich a position of the sheet-like elements is adjusted precisely andrapidly. A third objective is to produce an arrangement that allows apositional offset of the sheet-like elements to be corrected withoutentailing a stoppage phase for subsequent lamination. A fourth objectiveis to provide a positioning arrangement for a laminating unit thatavoids the problems of the prior art. Yet another objective is to createa laminating unit that has an arrangement that operates at high speedand that allows a positioning and correction of the sheets.

According to one aspect of the present invention, a method is developedfor manufacturing a multi-layer composite by laminating a sheet-likeelement onto a backing in a laminating unit. The method comprises, inthis order, the following successive steps:

-   -   a step of conveying the sheet-like element in a longitudinal        direction,    -   a step of conveying the backing in the longitudinal direction,    -   a step of detecting a position of this sheet-like element,    -   a step of correcting the position of this sheet-like element on        the basis of the position detected during the detection step and        on the basis of a reference position, and    -   a step of bonding this sheet-like element onto the backing.

In this method, the detection step comprises the following phases:

-   -   a phase of measuring a lateral position of the sheet-like        element,    -   a phase of measuring an angle of pivoting of this sheet-like        element, and    -   a phase of measuring a longitudinal position of this sheet-like        element.

In this method, the step of correcting the position of this sheet-likeelement notably comprises further the following steps:

-   -   a phase of moving the sheet-like element laterally,    -   a phase of pivoting this sheet-like element, and    -   a phase of moving this sheet-like element longitudinally.

In other words, with the method, the various measurement phases areseparate. The various phases of moving and pivoting are designed tocover all possible movements for a sheet-like element moving in a planeas far as the laminating step. The method is implemented without anystop or abutment of the sheet-like-elements and backings.

In another aspect of the invention, an arrangement for positioningsheet-like elements on backings to manufacture a multi-layer compositein a laminating unit, comprises:

-   -   detection means for detecting a position of the sheet-like        element, and    -   conveying and correction means for conveying and of correcting        the position of this sheet-like element, on the basis of the        position detected by the detection means and on the basis of a        reference position.

The conveying and correction means comprises:

-   -   means for moving this sheet-like element laterally, and    -   means for pivoting this sheet-like element and for moving it        longitudinally, which means is secured to the lateral-movement        means so as to perform a lateral correction, an        angle-of-pivoting correction, and a longitudinal correction.

In other words, an additional lateral-movement means is added to themeans that performs pivoting and longitudinal movement. All ranges ofdistances for the incorrect position of the sheet-like element arecovered and can be corrected. The pivoting and longitudinal-movementmeans moves laterally. In addition, with the positioning arrangement,the function of lateral movement, the function of pivoting and thefunction of longitudinal movement are separate and controlledindependently. These same functions can be used alone or in combinationwith one another.

According to yet another aspect of the invention, a laminating unitcomprises a section for feeding the sheet-like elements, a section forfeeding the backings, a section for laminating the sheet-like elementsonto the backings, and an arrangement for positioning the sheet-likeelements that has one or more of the technical features described andclaimed hereinbelow.

The upstream and downstream directions are defined with reference to thedirection in which the sheet-like elements and the backings travel inthe longitudinal direction through the arrangement for positioningsheet-like elements and through the laminating unit. The longitudinaldirection is defined with reference to the direction in which thesheet-like elements and the backings travel through the arrangement forpositioning sheet-like elements and through the laminating unit alongtheir central longitudinal axis. The transverse or lateral direction isdefined as being the direction perpendicular to the direction of travelof the sheet-like elements and of the backings in the plane formed bysuch sheet-like elements and backings respectively.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be clearly understood and its various advantages andfeatures will become better apparent from the following description ofthe non-limiting exemplary embodiment given with reference to theattached schematic drawings in which:

FIG. 1 depicts a simplified partial side view of a laminating unit;

FIGS. 2 to 7 depict the various steps in the method for manufacturing amulti-layer composite by laminating according to the invention;

FIG. 8 depicts a transverse view of a positioning arrangement accordingto the invention;

FIG. 9 depicts a view in section of a head of the arrangement, thesection being taken on the plane IX-IX of FIG. 8.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As shown in FIG. 1, a machine for producing a multi-layer compositecomprises a laminating unit (1). The unit (1) can be arranged forinstance at the exit of a corrugating machine (not shown) that produce asingle-face corrugated web. The unit (1) can also be fed by an unwinder(not shown), if the single-face corrugated web comes from a reel. Thesingle-face corrugated web is then cut into a cutting section (notshown) to produce individual backings (2). The unit (1) can alsocomprise a feed section (not shown) for the individual backings (2). Thefeed section is for example, in the form of a board feeder, theindividual backings (2) being initially arranged in a pile. This type ofassembly is known as being a sheet-to-sheet laminator.

The backings (2) are supplied continuously from the longitudinalupstream direction downstream (Arrow F) by a first conveying section(3), for example in the form of a first endless belt. At this stage, theunit (1) comprises an adhesive-coating or gluing section (not depicted),in which glue is applied to the upper face of the backings (2).

At the downstream exit of the first conveying section (3), the backing(2) is conveyed in the longitudinal direction (F) by a second conveyingsection (4), for example in the form of a second endless belt.

By virtue of the unit (1), sheet-like elements for instance in the formof individual printed sheets (6), are laminated onto the backings (2).The unit (1) in its upper upstream part can comprise a feed section (notdepicted) for the elements (6). The feed section is, for example, in theform of a sheet feeder, the elements being initially arranged in a pile.

The feed section causes the elements (6) to overlap one another and thusbring them into a continuous layer of shingled elements (6). Theshingled element stream is conveyed in the longitudinal direction (ArrowS) with a third conveying section (7), for example in the form of anendless belt.

The unit (1) next comprises a laminating section (8) positioned, on theone hand, in the second conveying section (4) and, on the other hand,downstream of the third conveying section (7). A convergence line forlamination for bonding the backing (2) to the element (6) is situatedbetween a bottom laminating roll (11) and a top laminating roll (12).

The backing (2) reaches the convergence line thanks to the secondconveying section (4). The element (6) reaches the convergence linethanks to an extension (9) of the third conveying section (7).

The element (6) is positioned and bonded onto the glue-coated backing(2). A multi-layer composite (13) is thus formed thanks to the rotatingof the laminating rolls (11 and 12) as the backing (2) and the element(6) simultaneously advance. The composite (13) leaves the unit (1)downstream (Arrow C). The composite (13) has an upper face consisting ofthe element (6) and an under face consisting of the backing (2).

The unit (1) comprises an arrangement (14) for positioning the element(6) very precisely on the backing (2). The arrangement (14) is installeddownstream of the third conveying section (7) and its extension (9) andupstream of the laminating section (8). The arrangement (14) is used tocorrect the position of the element (6) and laminate it between the twolaminating rolls (11 and 12).

A laminating method is performed by the unit (1) and comprises severalsteps, illustrated in FIGS. 2 to 7. The element (6) has beendeliberately depicted at a significant angle of pivoting that has to becorrected prior to lamination and in order to obtain a quality composite(13). The final adjusted position (15) of the element (6) correspondingto a reference position is partially represented.

In a first conveying step (FIG. 2), the element (6) is conveyed in thelongitudinal direction (Arrow L) toward the laminating section (8). Theelement (6) is conveyed using the extension (9).

In a second detecting step (FIGS. 3 to 5), the position of the element(6) is detected. According to the method of the invention, the detectionstep comprises three phases of measurements. In a first phase (see FIG.3), the lateral position of the element (6) is measured. In a secondphase (see FIGS. 4 and 5), the angle of pivoting of the element (6) ismeasured. In a third phase (see FIGS. 4 and 5), the longitudinalposition of the element (6) is measured.

In a third correcting step (FIGS. 6 and 7), the position of the element(6) is corrected. The correction is done by calculation, on the basis ofthe position detected during the second detection step, with the first,second and third phases of measurements, and on the basis of thereference position (15).

In a first example, the reference position (15) has been determinedbeforehand by the operator of the machine and corresponds to theposition that yields composites (13) of the best quality. Thepositioning of the elements (6) is programmable by the operator. Thereference position (15) can be recorded.

In a second example, the reference position (15) is determined a being afunction of the position of the backing (2) that advance being moved bythe first and second conveying sections (3 and 4). The laminating methodthus comprises another step positioned after the step of conveying thebacking (2) in the longitudinal direction and before the step ofcorrecting the position of the element (6). This additional stepconsists in detecting a position of the backing (2) and in calculatingthe reference position (15) according to the detected position of thebacking (2).

The phases of measuring the position of the element (6) in this secondstep and the phases of correcting the position of this element (6) inthis third step can be combined for greater speed and efficiency ofcorrection. By way of an advantageous embodiment, the method maycomprise accordingly the following successive phases positioned afterthe first conveying step.

In a first phase (see FIG. 3), the lateral position of the element (6)is measured. In this phase, the lateral edge (16) of the element (6) isdetected. In a second phase, the element (6) is moved laterally (Arrow Tin FIGS. 3 to 7). By way of preferred example, the lateral movement ofthe element (6) begins after the phase of measuring (FIG. 3) the lateralposition of the element (6). In a third phase (see FIGS. 4 and 5), thelongitudinal position and the angle of pivoting of the element (6) aremeasured and/or calculated. In this phase, the front edge (17) of theelement (6) is detected. In the preferred example, the lateral movement(T) may stop at the end of this third phase (FIG. 5). In a fourth phase(see FIG. 6), the element (6) is pivoted (Arrow P in FIG. 6). In a fifthphase, the element (6) is moved longitudinally (Arrow L in FIG. 7). Thelongitudinal movement (L) of the element (6) may take place throughoutthe correction step. In another example, the lateral movement (T) maystop at the moment when the element (6) reaches the convergence line inthe laminating section (16).

The detection step consists in reading one or more edges (16 and 17) ofthe element (6) and/or of the backing (2) in lateral or longitudinaldirection or also printed marks in lateral or longitudinal direction. Alateral mark or a front mark respectively printed on the surface of theelement (6) and/or of the backing (2) can be detected. The detection ofedges or marks depends on the type of detector used and on the registerwith printings desired.

In a fourth and final step (FIG. 7), the element (6) is bonded onto thebacking (2) with a gluing in the position sought by the operator.

The method may preferably further comprise a step of accelerating theelement (6) during the phases of pivoting (P) and longitudinally moving(L) the element (6) so as to be able to progress this element (6) from aconveying speed to a laminating speed. The laminating speed is higherthan the conveying speed.

The difference in speed is made up by accelerating the element (6). Inaddition, this acceleration allows the element (6) that is in the courseof undergoing the correction step to be separated from the upstreamelement following it that is still in the layer. This acceleration mayalso be of use in order to be able to create a gap between the firstelement (6) situated downstream and the next element (6) situatedupstream. This gap then serves properly to separate the rear edge of theelement (6) situated downstream from the front edge (17) of the nextelement (6) situated upstream. The front edge (17) can thus be clearlydetected, making it possible to measure the longitudinal position andangle of pivoting of the element (6).

The method may beneficially comprise a phase of holding the element (6)with a clamping, this phase being positioned before the conveying step,so as to allow all the lateral (T) and longitudinal (L) movements andall the pivoting (P) of the element (6). The method may advantageouslycomprise a phase of releasing the element (6), this phase beingpositioned after the start of the bonding step.

For preference, the method may comprise a step of accelerating and ofdecelerating the backing (2) so as to be able to create a gap betweenthe backing (2) situated downstream and the backing (2) situatedupstream. Accelerating makes it possible for the backing (2) situateddownstream to be extracted more swiftly and prevent it from being packedtogether with the next backing (2) situated upstream. The accelerationis managed by the second conveying section (4).

The arrangement (14) that corrects the position of the element (6) firstof all comprises means for detecting the position of the element (6).The detection means comprise a lateral detector (18). The lateraldetector (18) detects the arrival of the lateral edge (16) of theelement (6). The lateral detector (18) detects also the arrival of themark printed laterally on the surface of the element (6). The detectionmeans (2) additionally comprise two frontal detectors (19). Thesefrontal detectors (19) detect the arrival of the front edge (17) of theelement (6). The frontal detectors (19) detect also the arrival of themark printed at the front on the surface of the element (6).

The arrangement (14) that corrects the position of the element (6) maycomprise means for detecting the position of the backing (2) with adetector (not shown). The detector detects the arrival of the front edgeof the backing (2). The detector detects also the arrival of a markprinted at the front on the under face of the backing (2).

The arrangement (14) comprises means (21) for conveying and correctingthe position of this element (6) on the basis of the position detectedby the detection means (18 and 19) and on the basis of a referenceposition (15). The arrangement (14) with its conveying and correctingmeans (21) is mounted transversely with respect to the longitudinaldirection of travel of the elements (6).

According to the invention and as shown by FIGS. 8 and 9, the conveyingand correcting means (21) of the arrangement (14) comprise means (22)for the lateral movement of this element (6). The lateral-movement means(22) effects a lateral correction (T) on the element (6).

The conveying and correcting means (21) also comprise means (23) for thepivoting and longitudinal movement of this element (6). The pivoting andlongitudinal movement means (23) effects a correction to the angle ofpivoting (P) and a longitudinal correction (L) on the element (6). Thepivoting and longitudinal-movement means (23) is secured to thelateral-movement means (22). Because of the way in which it is mounted,the pivoting and longitudinal-movement means (23) moves laterally withrespect to the lateral-movement means (22).

Beneficially, the pivoting and longitudinal-movement means (23) maycomprise two independent heads (23 a and 23 b) able to drive the element(6). The heads (23 a and 23 b) are mounted so that they can slidetransversely with respect to the direction of travel of the element (6).The heads (23 a and 23 b) slide laterally and independently (see ArrowsH in FIG. 8) on the lateral-movement means (22).

The heads (23 a and 23 b) comprise sliders in the form of guides (24)mounted on the downstream side. The guides (24) engage withcorresponding slides (26) mounted on a cross member (27).

The lateral-movement means (22) may beneficially comprise a linearmotor, on which the means (23) for pivoting and for longitudinalmovement with the two heads (23 a and 23 b) may be mounted. The heads(23 a and 23 b) comprise the primary drive assembly (28), mounted on thedownstream side. The cross member (27) incorporates the secondaryassembly, known as the magnet track or magnetic track.

The lateral-movement means (22) is also used for positioning the twoheads (23 a and 23 b) in order to adjust the format of the element (6).

The heads (23 a and 23 b) may each incorporate a first motor (29) ableto collaborate with a bottom drive roller (31) in contact with an underface (32) of the element (6). Through a differential control (seedocument FR-2,857,655) of the two first motors (29) of the two heads (23a and 23 b), the two bottom rollers (31) rotates (Arrow R in FIG. 9) anddrive the element (6) in the longitudinal movement (L) and/or pivotingmovement (P). The two first motors (29) also generate all theaccelerations required for the element (6).

The phases of correcting the position are performed by virtue of thedifferential driving of the first motors (29) for performing the phasesof pivoting and of moving longitudinally the element (6), and of thelinear motor (22) for performing the phase of moving the elementlaterally.

The drive roller (31) may act in conjunction with a pressing device incontact with a top face (33) of this element (6). The pressing devicecomprises a top roller (34). The element (6) is caught and held betweenthe bottom drive roller (31) and the top roller (34).

Each head (23 a and 23 b) may comprise a lifting device (36) able tocause the top roller (34) of the pressing device to switch from aposition in which the element (6) is released into a position in whichit presses on and holds or clamps this element (6) and vice versa from aposition in which it holds the element (6) into a position in which theelement (6) is released. The lifting device (36) here is in the form ofan eccentric actuated by a second motor (37).

The front edge (17) of the element (6) reaches the arrangement (14) bybeing driven by the extension (9) of the third conveying section (7).Here, the second motor (37) is actuated and the top roller (34) of thepressing device go down to hold the element (6) (Arrow D in FIG. 9). Theelement (6) is then driven by the bottom drive roller (31) and the firstmotor (29).

When the front edge (17) of the element (6) enters through thelaminating section (8), the second motor (37) is actuated, the toproller (34) of the pressing device is raised back up (Arrow U in FIG. 9)and the top roller (34) releases consequently the element (6).

For preference, each head (23 a and 23 b) may comprise a decelerationdevice possibly able to cause the pressing device with its top roller(34) to progress from a rapid bonding speed to a slower conveying speed.The deceleration device comprises a third motor (38) driving a frictionroller (39). The friction roller (39) is able to rub against a frictionwheel (41), the latter being axially linked to the top roller (34).

When the element (6) is to be released, the pressing device causes theupper roller (34) to raise back up (U), the top roller (34) and thefriction wheel (41) become loose, the friction wheel (41) engages thefriction roller (39), the third motor (38) is thus actuated, and thefriction wheel (41) and the friction roller (39) are decelerated.

The present invention is not restricted to the embodiments described andillustrated. Numerous modifications may be made without therebydeparting from the context defined by the scope of the set of claims.

1. A method for manufacturing a multi-layer composite comprising, inthis order, the steps of: conveying a sheet-like element in alongitudinal direction toward a laminating unit, conveying a backing inthe longitudinal direction, detecting a position of the elementcomprising phases of measuring a lateral position, an angle of pivoting,and a longitudinal position of the element with reference to at leastone of the longitudinal direction and the laminating unit, correctingthe position of the element on the basis of the detected position and onthe basis of a reference position, the correcting step comprising thephases of lateral movement, pivoting, and longitudinal movement of saidelement, and bonding the element onto the backing by laminating thesheet-like element onto the backing in the laminating unit.
 2. Themethod according to claim 1, further comprising performing successivephases between the conveying step and the bonding step: the detecting isby measuring the lateral position of the element and then moving theelement laterally responsive to the detected and reference positions,the detecting is by measuring the longitudinal position of the elementwith reference to the laminating unit and then moving the elementlongitudinally responsive to the detected and reference position, andthe detecting is further by measuring the angle of pivoting of theelement and then pivoting the element responsive to the detected andreference positions.
 3. The method according to claim 1, furthercomprising a step of accelerating the element, during the phases ofpivoting and longitudinal movement of the element to cause the elementto accelerate from a conveying speed to a bonding speed higher than theconveying speed.
 4. The method according to claim 1, further comprisinga step of holding the element, positioned before the conveying step, anda step of releasing the element positioned after the start of thebonding step.
 5. The method according to claim 1, wherein the backingcomprises separate backing elements, each for having a respective one ofthe elements laminated to it; the method further comprising a step ofaccelerating and of decelerating the backing element, so as to create agap between each backing element upstream and a next backing elementdownstream in the longitudinal direction.
 6. The method according toclaim 1, further comprising a step of detecting a position of thebacking, and calculating the reference position according to thedetected position of the backing, this step being performed after thestep of conveying the backing in the longitudinal direction and beforethe step of correcting the position of the element.
 7. The methodaccording to claim 1, wherein the detection step comprises reading oneor more edges of the element or printed marks on the element, each inlateral or longitudinal direction.
 8. The method according to claim 6,wherein the detection step comprises reading one or more edges of thebacking or printed marks on the backing, each in lateral or longitudinaldirection.
 9. The method according to claim 2, further comprising a stepof holding the element, positioned before the conveying step, and a stepof releasing the element positioned after the start of the bonding step.10. An arrangement for positioning sheet-like elements on respectivebackings to manufacture a multi-layer composite in a laminating unit,comprising: respective devices for conveying the elements in successionand separately for conveying the backings in succession in alongitudinal direction toward the laminating unit; a detector configuredfor detecting a position of the element laterally and pivoted withreference to the longitudinal direction and in the longitudinaldirection devices for correcting the position of the element, on thebasis of the detected position and on the basis of a reference position,that comprise: a lateral-movement device configured for moving theelement laterally, and a pivoting device configured for pivoting theelement and a device configured for moving the element longitudinally,wherein the movement devices are configured to perform a lateral, anangle-of-pivoting, and a longitudinal, correction of the position of theelement.
 11. The arrangement according to claim 10, wherein the devicefor pivoting and the device for longitudinal movement comprises twoindependent heads configured for driving the element, and eachincorporating a motor collaborating with a drive roller in contact withthe element and operative for changing the position and orientation ofthe element.
 12. The arrangement according to claim 11, wherein thedrive roller is positioned in contact with an under face of the element,and acts in conjunction and a pressing device is positioned in contactwith a top face of said element wherein the drive roller and thepressing device act together on the element.
 13. The arrangementaccording to claim 12, wherein each of the heads comprises a liftingdevice configured and operable to switch the pressing device between aposition releasing the element and a position holding the element. 14.The arrangement according to claim 13, wherein the head furthercomprises an acceleration device configured and operable to cause thepressing device to progress from a bonding speed to a conveying speed.15. The arrangement according to claim 12, wherein the head furthercomprises an acceleration device configured and operable to cause thepressing device to progress from a bonding speed to a conveying speed.16. The arrangement according to claim 8, wherein the lateral-movementdevice comprises a linear motor on which the pivoting device and thedevice for longitudinal movement are mounted.
 17. A laminating unitcomprising a section for feeding sheet-like elements comprising in alongitudinal direction, a section for feeding backings in thelongitudinal direction and a section for laminating the sheet-likeelements onto respective backings, and an arrangement for positioningthe sheet-like elements according to claim 8.